Question

What are the solutions to the equation x2 = 81?

  A. 40.5 only   B. 40.5 and –40.5   C. 9 and –9   D. 9 only

Answer 1

C. 9 and -9

Explanation:

Answer 2

`x^2=81\ then\ x=9\ and\ x=-9\\\\because:(-9)^2=81\ and\ 9^2=81`



`x^2=81\to x=-√(81)\ and\ x=√(81)\to x=-9\ and\ x=9`